18F-FDG PET-CT Imaging Research Articles

Non-invasive assessment of programmed cell death ligand-1 expression using 18F-FDG PET-CT imaging in esophageal squamous cell carcinoma

Programmed cell death ligand-1 (PD-L1) is an ideal checkpoint for immunohistochemical detection. The method of obtaining PD-L1 expression through biopsy can impact the accurate assessment of PD-L1 expression due to the spatial and temporal heterogeneity of tumors. Because of the limited sample size, biopsies often give only a localized picture of the tumor. In this retrospective study, a total of 2,386 metabolic tumor volume (MTV) features were extracted from 18F-FDG PET-CT images. A radiomics model was developed to holistically and non-invasively assess PD-L1 expression in patients with esophageal squamous cell carcinoma by identifying seven independent factors through feature screening. The radiomics model shows effective discrimination, with an area under the receiver operating characteristic curve of 0.888 [95% confidence interval (CI): 0.831–0.945] and 0.889 (95% CI: 0.706–1.000) for the training and validation cohorts, respectively. The results of the decision curve analysis demonstrated that utilizing the radiation model to forecast PD-L1 expression levels yielded more net benefits at threshold probabilities below 0.669. The clinical impact curves demonstrate that when the threshold probability is less than 0.501, the loss-to-benefit ratio is less than one in all cases.

Assessing the metabolism of the olfactory circuit by use of 18F-FDG PET-CT imaging in patients suspected of suffering from Alzheimer’s disease or frontotemporal dementia

PurposeThe loss of olfactory function is known to occur in patients suffering from (behavioral variant) frontotemporal dementia ((bv)FTD) and Alzheimer’s disease (AD), although different pathophysiological mechanisms underpin this clinical symptom in both disorders. This study assessed whether brain metabolism of the olfactory circuit as assessed by positron emission tomography (PET) imaging with 2-[fluorine-18]fluoro-2-deoxy-d-glucose ([18F]-FDG) can distinguish these entities in different subsets of patients.MethodsPatients presenting with cognitive decline were included from a prospectively kept database: (1) bvFTD patients, (2) AD patients and (3) patients with logopenic primary progressive aphasia (PPA). Metabolic rates were calculated for different regions of the olfactory circuit for each subgroup and compared with a cohort of subjects with normal brain metabolism. Additionally, in patients with a logopenic PPA pattern on PET-imaging, statistical parametric mapping (SPM) analysis was performed.ResultsThe metabolism of subdivisions of the olfactory circuit as assessed by [18F]-FDG PET brain imaging to bvFTD and AD from control subjects resulted in sensitivity/specificity rates of 95/87.5% and 80/83.3%, respectively. A sensitivity/specificity rate of 100/87.5% was achieved when used to differentiate AD from bvFTD. In patients with the PPA pattern on imaging, the underlying cause (either FTD or AD) could be determined with a sensitivity/specificity rate of 88/82%. SPM analysis concurred that different regions of the olfactory circuit were affected in patients suffering from AD PPA or bvFTD PPA.ConclusionMetabolic dysfunction in the olfactory circuit is different in various neurodegenerative disorders. Further investigation of the correlations between the cerebral metabolism and the mechanisms which drive olfactory dysfunction is needed.

Association of Cardiovascular Risk Factors and Coronary Calcium Burden with Epicardial Adipose Tissue Volume Obtained from PET-CT Imaging in Oncological Patients.

Whole-body positron emission tomography (PET)-computed tomography (CT) imaging performed for oncological purposes may provide additional parameters such as the coronary artery calcium (CAC) and epicardial adipose tissue (EAT) volume with cost-effective prognostic information in asymptomatic people beyond traditional cardiovascular risk factors. We evaluated the feasibility of measuring the CAC score and EAT volume in cancer patients without known coronary artery disease (CAD) referred to whole-body 18F-FDG PET-CT imaging, regardless of the main clinical problem. We also investigated the potential relationships between traditional cardiovascular risk factors and CAC with EAT volume. A total of 109 oncological patients without overt CAD underwent whole-body PET-CT imaging with 18F-fluorodeoxyglucose (FDG). Unenhanced CT images were retrospectively viewed for CAC and EAT measurements on a dedicated platform. Overall, the mean EAT volume was 99 ± 49 cm3. Patients with a CAC score ≥ 1 were older than those with a CAC = 0 (p < 0.001) and the prevalence of hypertension was higher in patients with detectable CAC as compared to those without (p < 0.005). The EAT volume was higher in patients with CAC than in those without (p < 0.001). For univariable age, body mass index (BMI), hypertension, and CAC were associated with increasing EAT values (all p < 0.005). However, the correlation between the CAC score and EAT volume was weak, and in multivariable analysis only age and BMI were independently associated with increased EAT (both p < 0.001), suggesting that potential prognostic information on CAC and EAT is not redundant. This study demonstrates the feasibility of a cost-effective assessment of CAC scores and EAT volumes in oncological patients undergoing whole-body 18F-FDG PET-CT imaging, enabling staging cancer disease and atherosclerotic burden by a single test already included in the diagnostic work program, with optimization of the radiation dose and without additional costs.

Impact of Respiratory-gated 4D PET/CT Scan for Motion Correction in Characterizing Lesions Adjacent to the Diaphragm - A Cross-sectional Study at a Tertiary Care Institute.

The blur introduced by breathing motion degrades the diagnostic accuracy of whole-body F-18 fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) in lesions adjacent to the diaphragm by increasing the apparent size and by decreasing their metabolic activity. This study aims to evaluate the efficacy of motion correction by four-dimensional phase-based respiratory-gated (RG) 18F-FDG PET-CT in improving metabolic parameters of lesions adjacent to the diaphragm (especially in the lungs or liver). Eighteen patients with known lung or liver lesions underwent conventional 18F-FDG PET-CT and respiratory-gated PET-CT acquisition of the desired region using a pressure-sensing, phase-based respiratory-gating system. Maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were obtained for these lesions from gated and nongated PET-CT images for analysis. Furthermore, a visual analysis of lesions was done. Statistical significance of the RG image parameters was assessed by the two-tailed paired Student's t test and confirmed with the robust nonparametric Wilcoxon's signed-rank test (two-tailed asymptotic). There was an overall significant increase in SUVmax (P 0.001) in all gating methods with a percentage increase maximum of about 18.13%. On gating methods, MTV decreased significantly (P = 0.001) than that of nongating method (maximum reduction of about 32.9%). There was a significant difference (P = 0.02) in TLG between gated and nongated methods. Motion correction with phase-based respiratory gating improves the diagnostic value of 18F-FDG PET-CT imaging for lung and liver lesions by more accurate delineation of the lesion volume and quantitation of SUV and can thus impact staging, diagnosis as well as management in selected patients.

The Utility of [18]F-Fluorocholine Positron Emission Computed Tomography and [18]F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in Evaluating Breast Cancer Phenotypes: A Pilot Study.

The utility of the [18]F fluorodeoxyglucose positron emission tomography-computed tomography ([18]F FDG PET-CT) marker for breast cancer is well established. Given its limitations in localizing FDG-negative malignant tumors, the expression of [18]F-fluorocholine ([18]-FCH) may potentially be helpful to improve the overall accuracy in evaluating breast cancer. This study determined the potential of [18]- FCH PET CT as a potential marker in assessing breast cancer phenotypes. We recruited consecutive patients with biopsy-proven breast carcinoma who underwent [18] F-FCH PET-CT following the [18]F-FDG PET-CT imaging. The subjects were dichotomized into human epidermal growth factor receptor 2 (HER2)-negative and HER2-positive genotypes. The maximum standardized uptake value (SUVmax; g/dL) was used to predict the two groups of variables. Global health status (GHS) score based on the EORTC quality of life questionnaire (QLQ) was used to evaluate the outcome of the cohort subjects at 6, 12, and 24 months. There were 21 females with a mean age of 54.48 ± 12.17 years. Eighteen patients had invasive ductal carcinoma (18/21;85.8%) on histology, with 11 (52.4%) were HER2-negative genotype. There was higher sensitivity and specificity of [18]-FCH-PET/CT in breast lesions at 40% and 68.8% compared to [18]FDGPET/CT with 33.3% and 66.7%, respectively. There were significant differences between [18]F-FCH SUVmax (g/dL) of the HER-negative as compared to the HER2- positive group (1.99 g/dL vs. 0.2 g/dL; P < .05). High SUVmax (g/dL) of [18]F-FCH had predicted the HER-negative genotype at the cutoff value of 0.75 (P < .05). High [18]F-FCH showed significantly poor scoring of GHS parameters compared to low FCH at 6 months (mean SUVmax 8.06 vs. 5.40 respectively; P < .05). [18]F-FCH PET-CT is a potential marker in localizing and predicting aggressive breast carcinoma phenotypes.

Predicting T-Cell Lymphoma in Children From 18F-FDG PET-CT Imaging With Multiple Machine Learning Models

This study aimed to examine the feasibility of utilizing radiomics models derived from 18F-FDG PET/CT imaging to screen for T-cell lymphoma in children with lymphoma. All patients had undergone 18F-FDG PET/CT scans. Lesions were extracted from PET/CT and randomly divided into training and validation sets. Two different types of models were constructed as follows: features that are extracted from standardized uptake values (SUV)-associated parameters, and CT images were used to build SUV/CT-based model. Features that are derived from PET and CT images were used to build PET/CT-based model. Logistic regression (LR), linear support vector machine, support vector machine with the radial basis function kernel, neural networks, and adaptive boosting were performed as classifiers in each model. In the training sets, 77 patients, and 247 lesions were selected for building the models. In the validation sets, PET/CT-based model demonstrated better performance than that of SUV/CT-based model in the prediction of T-cell lymphoma. LR showed highest accuracy with 0.779 [0.697, 0.860], area under the receiver operating characteristic curve (AUC) with 0.863 [0.762, 0.963], and preferable goodness-of-fit in PET/CT-based model at the patient level. LR also showed best performance with accuracy of 0.838 [0.741, 0.936], AUC of 0.907 [0.839, 0.976], and preferable goodness-of-fit in PET/CT-based model at the lesion level. 18F-FDG PET/CT-based radiomics models with different machine learning classifiers were able to screen T-cell lymphoma in children with high accuracy, AUC, and preferable goodness-of-fit, providing incremental value compared with SUV-associated features.

Incidentally detected 18 F-FDG PET-CT-avid thyroid nodules in patients with advanced malignancy: long-term oncological outcomes from a single-centre retrospective cohort.

In this retrospective study, we assessed the clinical outcomes of patients with a primary malignancy who had incidentally detected thyroid avidity on their staging 18 F-fluorodeoxyglucose PET-computed tomography ( 18 F-FDG PET-CT) examinations. A focused retrospective search was made using a Radiology Information System to identify only patients with positive thyroid nodules on their 18 F-FDG PET-CT imaging between January 2012 and December 2017. Patient demographics, principal oncological diagnosis, and stage were recorded. The sonographic appearances of thyroid nodules, number of fine needle aspiration (FNA) attempts, final cytology, management plan, and clinical outcome were recorded. Follow-up records were available for between 2 and 7 years. Following exclusions, 136 patients were found to have incidental thyroid avidity on their 18 F-FDG PET-CT. A total of 50 of these patients proceeded to thyroid ultrasound assessment. Of these, 37 patients underwent FNA (average 1.3 FNA attempts) with 17 having atypical cytology and 6 diagnosed with an incidental thyroid cancer either by FNA or thyroidectomy. Four patients who underwent surgery had benign pathology. All thyroid cancers identified were indolent papillary cancers without any impact on the treatment plan or survival. The clinical outcomes of patients with an established primary malignancy are determined by their primary cancer and not by incidentally detected thyroid cancer. It may therefore be reasonable not to formally investigate a proportion of incidental 18 F-FDG PET-CT positive thyroid nodules where added benefit is unlikely. In such cases, a 'watch-and-wait' approach to the thyroid might be considered more appropriate.

Early prediction of residual disease after neoadjuvant chemoradiotherapy and cetuximab for locally advanced esophageal cancer using 18F-FDG PET-CT imaging: a prospective cohort study

Previous studies in locally advanced esophageal cancer (LAEC) suggested that a change in the tumor's metabolic response, i.e., decrease of its interim 18F-FDG uptake compared with baseline, may predict histopathological response. We evaluated the possible predictive correlation between various PET-CT and histopathological parameters following a neoadjuvant biological-containing chemoradiotherapy (CRT) regimen. Patients with resectable LAEC received neoadjuvant cisplatin/5-fluorouracil-based CRT and cetuximab following one cycle of induction chemotherapy and cetuximab. Changes in maximum and mean standardized uptake values (ΔSUV-max and ΔSUV-mean, respectively) and metabolic tumor volume (ΔMTV), measured by PET-CT at baseline and 2 weeks after the onset of treatment, were compared with histopathological findings at surgery. Histopathological response was defined by tumor regression grade (TRG), pathological complete response (pCR) and microscopic or macroscopic residual disease (RD). Of 18 patients, 13 (72%) with adenocarcinoma (AC) and 5 (28%) with squamous cell carcinoma (SCC), were included. None of the changes in the parameters of PET was associated with pCR; only ΔSUV-mean was associated with TRG in the AC cohort. In contrast, both ΔSUV-mean% and ΔSUV-max% were significantly associated with RD, both in the whole cohort and in the AC cohort. Changes in FDG-uptake predicted RD2 at surgery: only patients with less than 13% decrease in SUV-mean% or less than 29% decrease in SUV-max% had RD2, while all patients with RD0 or RD1 had greater reductions [100% specificity and 100% positive predictive value (PPV)]. Changes in ΔSUV-max and ΔSUV-mean after two weeks of onset of cetuximab-based neoadjuvant chemotherapy for LAEC may predict macroscopic RD but not TRG or pCR at surgery.

Comparison of Conventional Imaging and 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Diagnostic Accuracy of Staging in Patients with Intrahepatic Cholangiocarcinoma.

We aimed to examine the accuracy of tumor staging of intrahepatic cholangiocarcinoma (ICC) by using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET-CT). From January 2001 to December 2021, 202 patients underwent PET-CT, CT, and MRI for the initial staging of ICC in two institutions. Among them, 102 patients had undergone surgical treatment. Ninety patients who had a histopathological diagnosis of ICC were retrospectively reviewed. The sensitivity and specificity of 18F-FDG PET-CT, CT, and magnetic resonance imaging (MRI) in detecting tumors, satellite focus, vascular invasion, and lymph node metastases were analyzed. Ninety patients with histologically diagnosed ICC were included. PET-CT demonstrated no statistically significant advantage over CT and MR in the diagnosis of multiple tumors and macrovascular invasion, and bile duct invasion. The overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET-CT in lymph node metastases were 84%, 86%, 91%, 84%, and 86%, respectively. PET-CT revealed a significantly higher accuracy compared to CT or MRI (86%, 67%, and 76%, p &lt; 0.01, respectively) in the diagnosis of regional lymph node metastases. The accuracy of tumor staging by PET-CT was higher than that by CT/MRI (PET-CT vs. CT vs. MRI: 68/90 vs. 47/90 vs. 51/90, p &lt; 0.05). 18F-FDG PET-CT had sensitivity and specificity values for diagnosing satellite focus and vascular and bile duct invasion similar to those of CT or MRI; however, PET-CT showed higher accuracy in diagnosing regional lymph node metastases. 18F-FDG PET-CT exhibited higher tumor staging accuracy than that of CT/MRI. Thus, 18FDG PET-CT may support tumor staging in ICC.

Unusual Recurrence of Malignant Melanoma After 14 Years, diagnosed by 18F-FDG PET-CT Imaging: A Case Report

According to the World Health Organization, the number of malignant melanoma cases increases faster worldwide. Early diagnosed and adequately managed malignant melanoma shows a good prognosis. Rare cases of late metastasis of melanoma after long disease free survival, and their growing incidences are reported. This reported case is about a metastatic malignant melanoma who was apparently disease free for 14 years but showed late recurrence and earned clinical interest. A 60-year-old male patient was referred to PET-CT division of National Institute of Nuclear Medicine &amp; Allied Sciences (NINMAS) for the evaluation of a biopsy proven malignant melanoma in right inguinal region. The patient presented with a newly developed asymptomatic nodule on his right thigh. Relevant past medical history included a completely excised lesion in his left axilla for malignant melanoma. Fine-needle aspiration and cytological analysis report of new lesion showed subcutaneous localization of malignant melanoma. 18F-FDG PET-CT imaging showed hypermetabolic soft tissue density mass in right inguinal region; Histopathology report (HPR) proved malignant lesion. Multiple hypermetabolic lesions were seen intra abdominally involving spleen and pancreas with corresponding hypodense lesions on CT scan. Multiple hypermetabolic enlarged intraabdominal, right axillary and right inguinal lymph nodes are also evident. After 14 years of disease free survival the reported case developed malignant melanoma with distal metastases. Although late metastasis is uncommon however physicians should be aware of any newly developed suspicious lesions and PET-CT can play an important role in workup for detection of metastases from melanoma. Bangladesh J. Nuclear Med. 25(1): 45-47, 2022

Lung cancer Detected as a Metachronous Second Primary Malignancy in a patient with Pyriform Sinus Carcinoma during 18F FDG PET-CT scan

Pyriform sinus squamous cell carcinoma is the most prevalent type of hypopharyngeal carcinoma. The presence of a second primary malignancy in pyriform sinus carcinoma is uncommon. We present a case of metachronous second primary lung cancer detected by whole-body 18F-FDG PET-CT imaging during the follow-up evaluation in a treated case of well-differentiated squamous cell carcinoma of the left pyriform fossa. Bangladesh J. Nuclear Med. 24(1&amp;2): 64-67, 2021

Superscan on 18F-FDG PET-CT imaging for lymphoma: How frequent is it?

This retrospective study was conducted to evaluate the frequency of PET superscan in baseline staging scans of lymphoma patients.The study was conducted at the Shaukat Khanum Memorial Cancer Hospital, Lahore, from October 1, 2018 to August 31, 2019. A retrospective review of baseline PET-CT scans of 203 lymphoma patients, performed during the period of October 1, 2017 to August31,2018, was done from the institutional database. Out of these 203 patients, PET superscan pattern was observed in 13 (6.4%) patients, 08 (61.5%) males and 05 (38.5%) females. Eight (61.5%) patients had Non-Hodgkin's lymphoma, while 05 (38.5%)had Hodgkin's lymphoma. Based on TNM staging 10 (76.9%) patients had stage IV disease, 01 (07.6%) had stage III disease, and 2 (15.4%) had stage II disease. PET-CT superscan pattern is uncommon and is not dependent on the stage of the disease. It should be recognised in clinical practice as it suggests a poor prognosis.

Early Post-ischemic Brain Glucose Metabolism Is Dependent on Function of TLR2: a Study Using [18F]F-FDG PET-CT in a Mouse Model of Cardiac Arrest and Cardiopulmonary Resuscitation

PurposeThe mammalian brain glucose metabolism is tightly and sensitively regulated. An ischemic brain injury caused by cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) affects cerebral function and presumably also glucose metabolism. The majority of patients who survive CA suffer from cognitive deficits and physical disabilities. Toll-like receptor 2 (TLR2) plays a crucial role in inflammatory response in ischemia and reperfusion (I/R). Since deficiency of TLR2 was associated with increased survival after CA-CPR, in this study, glucose metabolism was measured using non-invasive [18F]F-FDG PET-CT imaging before and early after CA-CPR in a mouse model comparing wild-type (WT) and TLR2-deficient (TLR2−/−) mice. The investigation will evaluate whether FDG-PET could be useful as an additional methodology in assessing prognosis.ProceduresTwo PET-CT scans using 2-deoxy-2-[18F]fluoro-D-glucose ([18F]F-FDG) tracer were carried out to measure dynamic glucose metabolism before and early after CPR. To achieve this, anesthetized and ventilated adult female WT and TLR2−/− mice were scanned in PET-CT. After recovery from the baseline scan, the same animals underwent 10-min KCL-induced CA followed by CPR. Approximately 90 min after CA, measurements of [18F]F-FDG uptake for 60 min were started. The [18F]F-FDG standardized uptake values (SUVs) were calculated using PMOD-Software on fused FDG-PET-CT images with the included 3D Mirrione-Mouse-Brain-Atlas.ResultsThe absolute SUVmean of glucose in the whole brain of WT mice was increased about 25.6% after CA-CPR. In contrast, the absolute glucose SUV in the whole brain of TLR2−/− mice was not significantly different between baseline and measurements post CA-CPR. In comparison, baseline measurements of both mouse strains show a highly significant difference with regard to the absolute glucose SUV in the whole brain. Values of TLR2−/− mice revealed a 34.6% higher glucose uptake.ConclusionsThe altered mouse strains presented a different pattern in glucose uptake under normal and ischemic conditions, whereby the post-ischemic differences in glucose metabolism were associated with the function of key immune factor TLR2. There is evidence for using early FDG-PET-CT as an additional diagnostic tool after resuscitation. Further studies are needed to use PET-CT in predicting neurological outcomes.

A shining heart at Valentine's Day

A 60-year-old men was admitted mid-January for acute left abdominal pain. He had no medical history and didn’t smoke or take any medication. Abdominal CT-scan showed a voluminous (61 × 57 × 47 mm), heterogeneous, hemorrhagic mass in left adrenal gland with a high spontaneous density (45UH). Pheochromocytoma diagnosis was first suspected although 24-hours urine fractionated metanephrines and catecholamines measurements were only slightly increased (NA:1.1xULN and NMN:1.2xULN). Hormonal evaluation did not demonstrate excessive cortisol or sexual steroids secretion. 18F-FDG PET-CT imaging revealed intense FDG-uptake in the left adrenal gland as well as in the right adrenal gland and in the heart. With this new information, the differential diagnosis includes carcinoid cardiac tumor, malignant cardiac myxoma, sarcoma and metastases. All others tumor markers were negative (5HIAA, NSE, CA 19-9, CA 125, CEA, PSA, β-hCG). For Valentine's Day, cardiac MRI confirmed a pathological thickening of right inter-atrioventricular groove with marked late enhancement at this level, corresponding to pathological areas in isotopic imaging. Next day, patient presented acute right flank pain similar to the one he had on left side one month earlier. New abdominal CT-scan showed a large hemorrhage in right adrenal gland that was not present on 18F-FDG PET-CT performed 3 days before. Latest Ga-DOTATATE-PET imaging didn’t show anywhere STT-receptors presence. Morning cortisol level (411 nmol/L) remained non-suggestive of adrenal insufficiency. This case was discussed by web-conference with the French experts of the national COMETE multidisciplinary committee: it was decided to obtain histology from left adrenal tumor by percutaneous biopsy rather than by unilateral adrenalectomy because the radicality of surgery might change depending on histological diagnosis. So far, diagnosis has not yet been established. This case underlines importance of discussing complex situations with experts as allowed by COMETE or ENDO-ERN networks.

68Ga-PSMA-11 PET-CT vs. 18F-FDG PET-CT and MR perfusion-weighted imaging in preoperative cerebral gliomas diagnostics and histological grade prediction

68Ga-PSMA-11 PET-CT vs. 18F-FDG PET-CT and MR perfusion-weighted imaging in preoperative cerebral gliomas diagnostics and histological grade prediction

Usefulness of 18f-FDG PET-CT in Staging, Restaging, and Response Assessment in Pediatric Rhabdomyosarcoma.

Rhabdomyosarcoma is the most common soft-tissue sarcoma of childhood. Despite clinical advances, subsets of these patients continue to suffer high morbidity and mortality rates associated with their disease. Following the European guidelines for 18F-FDG PET and PET-CT imaging in pediatric oncology, the routine use of 18F-FDG PET-CT may be useful for patients affected by rhabdomyosarcoma, in staging, in the evaluation of response to therapy, and for restaging/detection of relapse. The European Pediatric Protocols are very old, and for staging and restaging, they recommend only radionuclide bone scan. The 18F-FDG PET-CT exam is listed as an optional investigation prescribed according to local availability and local protocols in the investigations panel required at the end of the treatment. We present two cases highlighting the usefulness of 18F-FDG PET-CT in managing pediatric patients affected by rhabdomyosarcoma, providing some bibliographic references.

The Use of a Visual Four-Score Scale Improves the Yield of 18F-FDG PET-CT Imaging in the Diagnosis of Cyst Infection in Patients with Autosomal Dominant Polycystic Kidney Disease

The Use of a Visual Four-Score Scale Improves the Yield of 18F-FDG PET-CT Imaging in the Diagnosis of Cyst Infection in Patients with Autosomal Dominant Polycystic Kidney Disease

The use of a visual 4-point scoring scale improves the yield of 18F-FDG PET-CT imaging in the diagnosis of renal and hepatic cyst infection in patients with autosomal dominant polycystic kidney disease.

[18F]FDG PET/CT (PET/CT) proved useful in the diagnosis of renal and hepatic cyst infection (CyI) in patients with autosomal dominant polycystic kidney disease (ADPKD). However, the definition of CyI by PET/CT is unclear. Here, we characterize the [18F]FDG uptake in CyI in order to infer a visual 4-point diagnostic scale. All ADPKD patients hospitalized between 2007 and 2019 for suspected CyI and who underwent an [18F]FDG PET/CT scan were listed. CyI was defined by 5 concomitant criteria: fever ≥ 38 °C; abdominal pain; peak plasma CRP ≥ 70 mg/L; no other cause of inflammation; and favorable outcomes after antibiotics for ≥ 21 days. First, all PET/CT images were visually interpreted. Next, the [18F]FDG uptake around the suspected CyI was scored using a semiquantitative 4-point scale in comparison to blood and liver activities. Sixty [18F]FDG PET/CT scans were performed for suspected CyI in 38 ADPKD patients. Twenty-nine episodes met the gold-standard criteria for CyI. The visual assessment of PET/CT images reached a sensitivity of 73.1% and a specificity of 70.6%. Using the 4-point scale, an [18F]FDG score ≥ 3 (i.e., cyst uptake > liver) improved the specificity to 85.3%. [18F]FDG PET-CT is helpful in CyI diagnosis in ADPKD, and the use of a 4-point scoring of [18F]FDG uptake improves its diagnostic yield, with positive and negative predictive values of 78.3 and 78.4%, respectively. External validation is required.

Application value of 18F-FDG PETCT imaging in the clinical initial diagnosis and follow-up of primary lesions of cervical cancer.

BackgroundCervical cancer is a common malignant tumor in gynecology with a high death rate. his study aims to analyze the application value of 18F-fluorodeoxyglucose imaging examination (18F-FDG PETCT) imaging in the initial clinical diagnosis and follow-up examination of cervical cancer.MethodsThe clinical data of 71 patients with cervical lesions who were admitted to our hospital from March 2017 to March 2019 were retrospectively collected all patients underwent 18F-FDG PETCT examination. The results of the pathological examination were a benchmark to calculate the sensitivity, specificity, and accuracy of 18F-FDG PETCT imaging in the diagnosis of primary lesions of cervical cancer and the diagnosis of postoperative recurrence, residual, and metastasis.ResultsThere were 39 patients initially suspected, and 30 cases were diagnosed as cervical cancer by pathological examination, including 22 cases with squamous cell carcinoma, 4 cases with adenocarcinoma, 3 cases with carcinoma in situ, and 1 case with adenosquamous carcinoma. The maximum standard uptake (SUVmax) value was (10.36±5.22), and the patient’s lesions showed different degrees of increase of 18F-FDG metabolism. The necrotic area in the patient's lesion showed reduced/defect metabolism. The sensitivity of 18F-FDG PETCT imaging in the diagnosis of primary lesions of cervical cancer was 86.66%, specificity was 44.44%, and accuracy was 76.92%. In the 32 cases followed up for monitoring after the operation, 16 cases showed recurrence, metastasis, residual and other conditions, and 7 cases showed local recurrence/metastasis. 18F-FDG PETCT images showed: abnormal widening of the cervix, stump nodules/mass in the vagina, and rectal and bladder infiltration. All patients with local recurrence were treated with local tissue biopsy or surgical resection under 18F-FDG PETCT image localization. The diagnostic sensitivity, specificity and diagnostic coincidence rate of 18F-FDG PETCT imaging for postoperative follow-up of cervical cancer patients were 100%, 75.00% and 87.50%, respectively.ConclusionsFor patients with cervical cancer who are initially diagnosed or followed up, they can all be tested by 18F-FDG PETCT imaging, which can provide a reference for the formulation of diagnosis and treatment plan and the evaluation of prognosis.

Real-world experience of the role of 18F FDG PET-computed tomography in chronic spinal implant infection.

The presence of postinstrumentation back pain in patients after undergoing spinal surgery is a well established phenomenon. So too is the presence of infection, both overt and subclinical which can be a source of pain. The accurate assessment of infection in patients with spinal implants in situ and no overt radiological or biochemical abnormalities frequently presents a diagnostic challenge. We present our experience spanning 5 years of using 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (18F FDG PET)-computed tomography (CT) scans to aid the diagnostic process in treating presumed low-grade chronic implant infection. We undertook a retrospective analysis of all patients with spinal implants in place who were referred for 18F FDG PET-CT imaging over a 5-year period. All available images, case notes and laboratory results were reviewed. Data pertaining to 49 patients were analysed, with infection diagnosed on 18F FDG PET-CT in 24 (45%) of those sent for scanning. Fifteen patients in the cohort underwent revision surgery, and 11 of whom had been diagnosed as infected on PET-CT. Confirmation of infection with positive microbiological sampling occurred in 8/11 giving a positive predictive value of 0.72 in our series. We present a real-world experience of using 18F FDG PET-CT as a diagnostic tool in the evaluation of patients with chronic pain after undergoing spinal implantation. We have found PET-CT to be a promising modality and would recommend multicentre collaboration to ensure reproducibility across more centres.